This pattern doesn’t really suggest a yarn to use:
Materials:
Medium Weight Yarn (4)
13.5 ounces, 210 yards (100 grams, 192 meters) per skein: 3 skeins
29” (73.5 cm) circular knitting needle, size 8 (5 mm) or size needed for gauge
Marker
Gauge: in pattern,
one repeat (17 sts) = 4” (10cm)
and Rnds 5-13 = 1-1/2” (3.75 cm)